Drafting apparatus



March 17, 1936. EL MARIO 2,034,350

DRAFTING APPARATUS Filed April 21, 1934 s Sheets-Sheet 1 A T T ORNE Y5.

March 17, 1936. E. MARIO DRAFTING APPARATUS 3 Sheets-Sheet 2 Filed April21, 1934 INVENTOR. -1" 91 6414140 ATTORNEYS.

March 17, 1936. 5 MARK; 2,034,350

DRAFTING APPARATUS Filed April 21, 1934.

3 Sheets-Sheet 3 JNVENTOR.

M 972741010, BY M A TTORNEYS.

Patented Mar. 17, 1936 UNITED STATES -ATENT OFFICE 8 Claims.

This invention relates to a drafting apparatus and while it isparticularly adapted for use by v topographical draftsmen when makingmaps and charts, it may also be used by architects and engineers whendrawing plans.

One object of the invention is to provide a device of this characterwhich can be used for laying off straight or arcuate lines at any angledesired and also as a pr-otractor and thus permit a map or plan to bevery accurately drawn.

Another object of the invention is to so construct the device thata basebar thereof may be firmly secured upon a drafting table and adjusted toextend exactly horizontal, with a supporting rod or bar projectingtherefrom at right angles to the base bar or at a slight incline towardsthe upperor rear side of the table and thereby permit straight -orarcuate lines to be accurately plotted and drawn.

A still further object of the invention is to'provide for detachablymounting a ruler under the base bar and permit a protractor or straightedged ruler to be selectively connected with the supporting rod.

Another object of the invention is to provide a protractor of suchconstruction that either 'an arcuate line or entire circle may be drawnand also provide a straight edged ruler so associated with a circularscale that it may be turned within the confines of the scale with itsaxis coinciding with the center of the scale when the protractor is inuse.

Still another object of the invention'isto permit the device to be swungvertically into and out of position over the drawing table and alsoallow the circular scale to be shifted without danger of smearing adrawing.

Still a further object of the invention resides in providing a devicewhich is simple and durable in construction, inexpensive to manufactureand one which will be very efficient in application.

With these and numerous other objects in view, my invention consists inthe novel features of construction, combination and arrangement of partsas will be hereinafter referred to and more particularly pointed out inthe specification and claims.

In the accompanying drawings forming a part of this application;

Figure l is a top plan view showing the improved drafting device appliedto a table with a circular scale in use;

Figure 2 is a sectional view taken along the line 2-2 of Figure 1;

Figure 3 is a fragmentary view of the circular scale partially in topplan and partially in section;

Figure 4 is an enlarged sectional View taken along the line -44 ofFigure 3;

Figure 5 is a view in elevation looking from the 5 front of the table;

Figure -6 is a transversesection taken-along the line 6-5 of Figure 1;

Figure 7 is a fragmentary View showing a mounting forming part of thedevice, principally 10 in elevation and partially in section along theline l-i of Figure 8 Figure 8 is a section taken along the line 8-8 ofFigure 7;

Figure 9 is a sectional view taken horizontally through Figure 7;

Figure 10 is a section taken along the line it-lii of Figure 5 withportions of a securing clamp shown in section and other portions thereofinelevation; V 20 Figure 11 is a section through the clamp taken alongthe line l'l-Il of Figure 10;

Figure 12 is a section taken horizontally through the clamp along theline I2l2 of Figure 10;

Figure 13 is another sectional view taken horizontally through the clampalong the line l3-l3 of Figure 10;

Figure 14 is a top plan view showing straight edged rulers in use;

Figure 15 is a sectional view taken along the line iii-l5 of Figure 14;

Figure 16 is a perspective view showing the improved drafting deviceapplied to a table and equipped with the straight edged rulers.

This improved drafting implement has been shown applied to the top i ofa drafting table formed with a slot 2 through which an edge portion ofthe paper 3 is to project as shown clearly in Figures 2, l5 and 16, butit is to be understood that this merely illustrates one conventionalform of drawing table to which the device may be applied and also thatit may be applied to a drawing board instead of directly to a table top.

The base bar 4 is formed of strong angle metal and has a lowerhorizontal flange '5 from which projects an upstanding vertical flange 6formed with a longitudinally extending slot 1. At its ends the base baris formed with enlargements constituting feet 8 which support the basebar I in an elevated position as shown clearly in Figure 2 and fromthese enlarged ends of the base bar project arms '9 having clamps l0pivoted to their outer ends. These clamps normally extend in dependingrelation to the arms with their stationary jaws II in position to bearagainst the 5'5 upper face of the table top I and their adjusting screwsl2 below the table top. When the adjusting screws are rotated in adirection to move them upwardly into position to engage the under faceof the tabletop and are then tightened, the table top will be firmlygripped and the base bar will be securely held in operative relation tothe drawing table but since its arms are pivoted to the clamps, it maybe swung vertically towards or away from the table. In view of the factthat the paper 3 extends under the base bar, the paper will be preventedfrom curling or slipping out of place. Threaded rods or bolts I3 extendupwardly from the jaws I l near their free ends and carry springs I4against which the arms 9 rest when the arms are in position over thetable with the rod or threaded stem engaged through the oval opening l5formed in the arms. Nuts K5 are threaded upon the projecting upper endof the bolts l3 to limit upward movement of the arm and base bar or holdthe feet 8 of the base bar firmly against the paper if the securing nutsare sufficiently tight. 'It will thus be seen that the base bar maynormally have its feet spaced slightly from the paper or firmly held incontact therewith and that when the feet of the base bar are slightlyout of contact with the paper, this paper may be readily slid along thetable top and through the slot 3. By removing the nuts from the upperends of the rods or bolts l3, the base bar and its arms may be swungupwardly and then downwardly to a position in which the base bar andmechanism carried thereby will be suspended from the table adjacent anedge thereof, where it will be out of the way when not needed. As theopenings l5 are oval when viewed in top plan the arms 9 may movevertically without binding upon the bolts l3 but will be prevented fromhaving side play.

In order to detachably and adjustably connect a scale or ruler with thebase bar, a bracket I1 is employed which is formed of angle metal andhas a lower horizontal flange l8 and an upstanding vertical flange l9.The horizontal flange of the bracket rests upon the flange 5 of the basebar 4 and the flange H] has flat face-to-face contact with the flange 6and carries a threaded stem 20 which is passed through the slot 1 andhas threaded upon its free end portion a winged nut 2| which whentightened firmly secures the bracket in a set position. When this nut isloosened, the bracket may be slid longitudinally upon the base bar to adesired position where it will be again secured by tightening the nut.Openings 22 are formed through the upstanding flange of the bracket insuch position that they are exposed through the slot 1 as shown clearlyin Figures 5 and 7, thereby permitting a person to pass his fingersthrough these openings and easily slide the bracket to an adjustedposition. A mounting rod 23 extends transversely of the bracket atsubstantially right angles thereto and at one end carries a cross-head24 which rests upon the horizontal flange I 8 of the bracket where it issecured by bolts 25 and by referring to Figure .9, it will be seen thatone of these bolts is passed through a circular opening 26 formed nearone end of the cross-head while the other bolt passes through a slot 21extending trans- -versely of the cross-head adjacent the other endthereof. By this arrangement, the supporting bar or rod 23 may bedisposed exactly at right angles to the bracket and base bar and the twobolts 25 then tightened or the supporting bar may be set slightly out ofa position at right angles to the bracket and secured in this positionby tightening the bolts.

This improved drafting implement is to be used by topographicaldraftsmen when making maps or charts and by architects and engineerswhen drawing plans. I have, therefore, provided a protractor which maybe applied to the supporting rod 23 and includes in its makeup acircular scale 28 and straight edge ruler 29 and have also provided astraight edged ruler 30 to be connected with the supporting rod in placeof the protractor and a second straight edged ruler or scale 3| whichmay be mounted under the base bar when either the scale 30 or theprotractor are in use. It will be understood that the ruler or scale 30may be used without the scale 3| and also the protractor and inaddition, that the scale 3| may be used without the protractor or scale30 in which case the bracket H can be detached from the base bar andthereby allow full length use of the scale 3|.

The circular scale 28 of the protractor is formed of xylonite orcelluloid metal and has its upper face marked with appropriate scalemarkings as shown in Figure 1. A bridge 32 consisting of a metal rodhaving its ends turned downwardly and secured to the circular scale byscrews 33 passed upwardly through the circular scale, is disposed abovethis circular scale and extends across the same as shown in Figure 6 andby referring to Figure 1, it will be seen that this bridge or yoke doesnot extend diametrically of the circular scale in order that a zero mark34 provided at the center of the straight edged rule or scale 29 may bevisible.

A lug or bearing 35 which is firmly fixed to the bridge 32 at its centerextends downwardly therefrom and is formed with an opening slidablyreceiving the mounting rod 23 and the circular scale carries a block orbearing 36 through which the mounting rod is also passed. This block 36is equipped with a set screw 3! which when tightened will firmly holdthe protractor in an adjusted position longitudinally of the supportingrod. It will thus be seen that the protractor or circular scale can beadjusted longitudinally of the supporting rod and by loosening thewinged nut 2|, the circular scale together with the rod and bracket maybe adjusted longitudinally of the base bar. Therefore, this protractormay be adjusted longitudinally and transversely of the sheet of paperand disposed in a desired position relative to a map or plan beingdrawn.

The straight edged rule or scale 29 extends diametrically of thecircular scale within confines of its inner periphery and at its endscarries metal shoes 38 which are arcuate longitudinally and project fromopposite sides of the rule. Referring to Figure 4, it will be seen thateach shoe is secured to the rule or scale by a counter-sunk screw 39 andthat the outer marginal edge portion of the shoe is bevelled from itsupper and lower faces, thereby providing a tapered marginal portion 40which engages in a groove 4| of similar configuration formed in theinner marginal edge face of the circular scale. By this arrangement, theruler or straight edged scale 29 will be held diametrically of thecircular scale but may be turned the full circumference of the circularscale about an axis coinciding with the center of the circular scale andindicated upon the rule by the zero mark 34. Scale markings upon theupper face of the ruler increasingly progress from the zero mark towardsthe two ends of the ruler and as the zero mark is exposed and may be inthe form of a small opening, if so desired, it will be very easy to finda center upon a map or plan and also the straight edged rule or scalemay be accurately set to extend at any angle desired, where it will beheld due to frictional binding between the shoes 38 and walls of thegroove 4|. The openings 39 formed in ends of the scale 29 to receive thescrews 39 are elongated longitudinally of the scale as shown in Figure 4and, therefore, when contacting faces of the marginal portions 46 andWalls of the groove 4| become worn, the screws can be loosened to permitthe shoes to be slid longitudinally of the scale until they again fitsnugly within the groove 4| and the screws retightened. Therefore, wearcan be compensated for.

When the straight edged scale or ruler 3B is to be used in place of theprotractor, the protractor is removed by sliding it longitudinally offof the rod 23 after first loosening the screw 42 and removing the washer43 from the end of the rod. The rod is then slid through openings formedin the bearing blocks 44 and 45 which are firmly held upon the ruler byscrews 46 passed upwardly through the same and since the bearing block44 carries a set screw M, the ruler 30 may be firmly secured in a setposition and prevented from slipping longitudinally of the rod. Thisruler and the protractor may rest fiat upon the sheet of paper when inuse but by properly adjusting the nut It the spring l4 may yieldablysupport the base bar in a sufficiently elevated position to permitshifting of the scale across the paper without danger of blotting. Whilethe rulers or scales 3 and 3| may be used by engineers or architects,they are primarily intended for use for laying off or determininglongitude and latitude by map makers and topographical draftsmen.

When this improved drafting apparatus or implement is in use, the clampsID are applied to the table top or drawing board with the jaws II andsecuring screws l2 engaging upper and lower faces thereof. Care shouldbe taken to have the base bar 4 extend parallel to the slot 2 or theadjacent edge of the table top. When so secured, the base bar willextend over the sheet of paper and if a map is being drawn, a lineextending horizontally across the paper and indicating latitude may bebrought into proper parallel relation to a side edge of the lower flange5 of the base bar and the paper secured in a stationary position uponthe drawing table by contact or the nut [6 may be tightened sufficientlyto force the feet 8 of the base bar into clamping engagement with thesheet of paper. It is preferred, however, to have the feet of the basebar spaced slightly above the paper in order that the scale or rulersmay be moved across the paper, without danger of smearing and thenbrought into contact with the paper by pressure applied to the base barwhich will compress the spring l4 and move the scale and feet of thebase bar into contact with the paper. If the ruler or straight edgescale 3| is to be used, it is secured against the under face of the basebar by the screws shown in dotted lines in Figure 15. When this ruler isin place and the ruler or scale 30 is in use, the scale will be appliedto the mounting rod 23 with one end contacting with an edge of the ruler3| or the ruler or scale 30 may be slid along the rod 23 and releasablysecured in any desired position thereon. The protractor or circularscale may be used either with or without the rule 3| and by properlyadjusting this scale along the rod 23 and moving the bracket I! alongthe base bar, the circular scale may be shifted into any desiredposition for drawing arcuate or circular lines and also for drawingstraight lines at a desired angle through the medium of the scale 29. Bymoving the protractor into position over a compass rose provided uponthe drawing table or the sheet of paper, the scale 29 may be accuratelyset to extend at a desired angle and then moved into position fordrawing. When the device is not in use, the bracket can be easily andquickly detached from the base bar and together with the rod 23 and thescale put away and the clamps It] may then be loosened to permit removalof the base bar from the table or left in engagement therewith and thenut l6 unscrewed in order to permit the base bar to be swung from aposition over the table to a depending position at one side thereofwhere it will be out of the way.

From the foregoing description of the construction of my improveddevice, the operation thereof and the method of use will be readilyunderstood. It will be seen that I have provided a simple, inexpensiveand efficient means for carrying out the objects of the invention andwhile I have particularly described the elements best adapted to performthe functions set forth, it is obvious that various changes in form,proportion and in the minor details of construction may be resorted to,without departing from the spirit or sacrificing any of the principlesof the invention.

Having thus described the invention, what is claimed is:

1. A drafting implement comprising a mounting including a bar supportedin an elevated position, a circular scale disposed beneath said bar andsuspended from the same, a ruler extending diametrically of said scale,and arcuate shoes at ends of said ruler detachably connected therewithand slidably engaged in a circumferentially extending seat formed in theinner marginal edge face of the scale for movement about the innerperipheral edge thereof whereby the ruler may be turned about an axiscoincident with the center of the scale.

2. A drafting implement comprising a mounting including a base bar andmeans for connecting the base bar with a drawing board and mounting thebase bar for swinging movement towards and away from the upper face ofthe drawing board, depending feet at the ends of the base bar to supportthe base bar spaced above the drawing board, a supporting bar extendingtransversely of said base bar and connected therewith for adjustmentlongitudinally of the base bar, a scale extending longitudinally of saidbase bar beneath the same between the feet and detachably connected withthe base bar, said scale having a portion projecting forwardly from thebase bar to present an edge spaced forwardly therefrom in parallelrelation thereto and another scale disposed beneath said supporting barlongitudinally thereof and detachably connected therewith and extendingat right angles to the front edge of the first mentioned scale.

3. A drafting implement comprising a mounting including a base bar andmeans for connecting the base bar with a drawing board and mounting thebase bar for vertical swinging movement towards and away from the upperface of the drawing board, means for cushioning movement of the base bartowards the drawing board and yieldably holding the base bar spacedabove the drawing board, a bracket carried by said base bar andadjustable longitudinally thereof, a supporting bar extending atsubstantially right angles to said base bar and having one enddetachably connected with said bracket, and a scale carried by saidsupporting bar.

4. A drafting implement comprising a mounting including a base bar,depending feet at ends of said bar to support the bar spaced above adrawing board, arms extending from ends of the bar, clamps pivoted tosaid arms and having jaws beneath the arms, bolts rising from said jawsand passing through openings in the arms, springs between the arms andjaws yieldably resisting downward movement of the arms, nuts carried bysaid bolts and engaging the arms to hold the arms against said springs,a supporting bar extending transversely from said base bar, a scaledetachably carried by said supporting bar and a second scale detachablysecured under said base bar between said feet.

5. A drafting implement comprising a mounting including a horizontalbase bar adapted to have a scale associated therewith, arms extendingfrom the outer longitudinal edge of said bar, clamps pivoted to outerends of said arms and depending therefrom for engaging a drawing boardand mounting the base bar for vertical swinging movement towards andaway from the drawing board, means to cushion downward movement of thebase bar towards a drawing board and'urge the base bar upwardly andyieldably hold the base bar spaced above the drawing board, and meansfor controlling upward movement of the base bar by the yieldable means.

6, A drafting implement comprising a mounting including a base baradapted to have a scale associated therewith, arms extending from saidbar, clamps pivoted to said arms for engaging a drawing board andmounting the base bar for vertical swinging movement towards and awayfrom the drawing board, springs between the arms and portions of saidclamps to yieldably hold the base bar spaced above a drawing board, andmeans to hold the arms in engagement with the springs.

'7. A drafting implement comprising, a mounting including a barsupported in an elevated position, a circular scale disposed beneathsaid bar and suspended from the same, a ruler extending diametrically ofsaid scale'and having its end portions reduced from its under face toform seats, and shoes detachably secured in the seats at ends of saidruler and projecting from opposite sides thereof, the inner marginaledge face of the scale being grooved to form a circumferentiallyextending track and said shoes having tapered edge portions engaged inthe track to slidably connect the ruler with the scale for turning aboutan axis coincident with the center of the scale. 7

8. A drafting implement comprising a mounting including a base barformed of angle-material and having a horizontal flange and a verticalflange extending upwardly therefrom and formed with a longitudinallyextending slot, means for detachably securing said base bar upon adrawing board, a bracket formed of angle-material and having ahorizontal flange resting upon the horizontal flange of said base barand an upwardly extending vertical flange provided with a fastenerengaged through the slot to detachably connect the bracket with thevertical flange of the base bar and mount the bracket for adjustmentlongitudinally of the base bar, openings being formed in the verticalflange of the bracket and aligned with the slot whereby fingers may beengaged through the openings and the bracket slid along the base bar, asupporting bar detachably secured at one end to the horizontal flange ofsaid bracket and projecting therefrom transversely of the base bar, anda scale carried by the supporting bar.

EMILIO MARIO.

